1. Field of the Invention
The present invention relates to a blind fastener and more particularly to a weather tight blind fastener having a tubular member securing the pieces to be joined and a rod member also securing the pieces to be joined and held within the tubular member by a slidable plate member, a resilient washer and a rigid washer to provide a strong resilient weather tight fastener.
2. Description of the Prior Art
Blind fasteners are well-known in the prior art as exemplified by U.S. Pat. No. 2,030,166, U.S. Pat. No. 2,030,167, U.S. Pat. No. 2,501,567, and U.S. Pat. No. 3,232,162. These prior art patents utilize a flanged tubular member which is inserted through aligned holes in the items to be joined with the flanged head contacting one of the items. In U.S. Pat. Nos. 2,030,166 and 2,030,167 a headed rod member is disposed within a flanged tubular member with the headed portion contacting the unflanged end of the tubular member. When force is applied to the rod member the unflanged end of the tubular member collapses The flanged end of the female member has a rivet shaped head. The male member is held in the female member by a press fit with the female member. U.S. Pat. No. 2,030,166 teaches an undercut on the head of the rod member and collapsing of the tubular member into more than one pleat or bulb. When installed, the mandrel breaks at or beneath the head of the tubular member. In U.S. Pat. Nos. 2,501,567 and 3,232,162 a flanged tubular member is inserted through aligned holes in the items to be joined with the flanged head contacting one of the items. A rod member partially disposed in the hollow tubular member has an enlarged head which is drawn into the tubular member to expand the nonflanged end of the tubular member thus holding the items to be joined. In U.S. Pat. No. 2,501,567 the rod member is merely held in place by the frictional force when the blind fastener is installed. In U.S. Pat. No. 3,232,162 the rod member is rigidly held in place by metal flow from the hollow tubular member into a plurality of breakneck grooves formed on the rod member.
U.S. Pat. No. 3,851,559 illustrates a blind fastener which utilizes a radially expandable hollow cluster of helical filaments held together by their shape. When the cluster of filaments is axially compressed, the cluster undergoes, throughout the axial length, a uniform radial expansion. The filaments extending beyond the members joined spread, as a result of the axial compression, to hold the fastener in place.
Various types of threadless retaining plates are also disclosed in the prior art as exemplified by U.S. Pat. Nos. 3,205,758 and 3,796,124. U.S. Pat. No. 3,796,124 illustrates a circular plate fastening member, having a plurality of tongues, which is slidable in one direction only. This clamping member is not shown or suggested for use in combination with any type of blind rivet. The invention of U.S. Pat. No. 3,796,124 relates to a system for clamping corrugated sheet members to a rod of a roof structure. U.S. Pat. No. 3,205,758 teaches a threadless retaining plate constructed for use with a mandrel which is secured to a rigid backing or panel for holding an insulating blanket in place. A blind rivet is illustrated in this patent but merely for use in securing the mandrel to the panel backing. After the mandrels are secured by blind rivets to the panels, the insulating blanket is impaled over the mandrel and held in place by the threadless retaining plate, to which U.S. Pat. No. 3,205,758 is directed.
Although the blind fastener art is old and well developed there are still several problem areas. One problem is to provide a blind rivet which is easy to assemble and remains intact before installation. U.S. Pat. No. 2,030,166 suggests a press fit between the tubular member and the mandrel. This however requires close tolerance parts and complicates assembly. Another problem with prior art blind fasteners is that the items to be joined are held rigidly together only by the deformed tubular member. If the items being held loosen the deformed tubular member by expansion or movement they are no longer securely held in place but become somewhat loose. It is desirable to have a blind fastener wherein the members to be secured are resiliently held in place so that they will not become loose when slight movements occur. Slight movement can occur, especially in exterior fasteners, due to thermal expansion and contraction or due to other environmental variations. Yet another problem with some prior art blind fasteners is that the tubular member must be accurately sized to the length of the opening through the items. It is desirable to have a blind fastener which can accommodate a variety of material thickness without being specially sized. It is desirable to have a blind fastener wherein the sleeve or tubular member is deformed in a controlled fashion to secure various thickness materials and wherein the forming rod member is securely and resiliently held in place after installation to provide a weather tight seal and resilient holding of the members joined.